There are disclosed herein photoconductors, and more specifically, photoconductors containing a hole blocking layer or undercoat layer (UCL) comprised, for example, of metal oxide particles, and adhesion components that permit the excellent adhesion between, for example, the hole blocking layer and the substrate, and the layers thereover, such as the photogenerating layer and the charge transport layer or layers. More specifically, there are disclosed hole blocking layers comprised of a number of the components as illustrated in the copending applications referred to herein, such as a metal oxide like a titanium dioxide, a polymeric resin or polymeric resins, such as a phenolic resin, an acrylic resin, a styrene-acrylic resin or a melamine resin, and an adhesion promoter, examples of which are a polymeric phosphate ester, an ester of phosphoric acid or optionally mixtures thereof. Charge blocking layer and blocking layer are generally used interchangeably with the phrase “undercoat layer”.
Also included within the scope of the present disclosure are methods of imaging and printing with the photoresponsive or the photoconductive devices illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additives, reference U.S. Pat. Nos. 4,560,635; 4,298,697 and 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto. In those environments wherein the device is to be used in a printing mode, the imaging method involves the same operation with the exception that exposure can be accomplished with a laser device or image bar. More specifically, the photoconductors disclosed herein can be selected for the Xerox Corporation iGEN3® machines that generate with some versions over 100 copies per minute. Processes of imaging, especially xerographic imaging and printing, including digital, and/or high speed color printing, are thus encompassed by the present disclosure.
The imaging members disclosed herein are, in embodiments, sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source.